Metabolic effects of an oral carbohydrate-whey protein supplement after fasting in volunteers: A randomized...

Oral supplements containing carbohydrates (CHOs) can be used to reduce preoperative fasting time. The aim of this study was to investigate the early metabolic and acute phase responses to a clear, oral supplement containing CHO and whey protein (WP) in young, healthy volunteers during a fasting-induced organic response.

In this controlled crossover clinical trial, volunteers were randomized into groups after a 12-h fast: the CHO+WP group consumed 200 mL CHO enriched with WP (n = 30); the CHO group members consumed 200 mL water plus maltodextrin (n = 30), and the Fast group was fasted only (n = 30). Blood samples were collected after fasting and 3 h after ingestion of the supplement. The samples were analyzed for glucose, glycated hemoglobin, insulin, C-reactive protein, β-hydroxybutyrate, triacylglycerols, albumin, chlorine, and sodium. After 7 d, the groups were inverted, so all volunteers entered the three groups.

The nutritional intervention did not change the biochemical parameters related to the acute phase response or insulin resistance; however, there was a statistically significant reduction (P < 0.001) in serum β-hydroxybutyrate in the CHO+WP group (0.05 ± 0.08 mmol/L) compared with the other two groups (Fast group: 0.11 ± 0.08 mmol/L; CHO group: 0.09 ± 0.13 mmol/L).

After overnight fasting, the oral supplement containing CHO and WP decreased ketosis. These findings may help select the most efficient oral supplement to be given 2 to 3 h before elective surgeries.